@quant_dev - That link from petachem shows the time evolution of a protein at an ab initio level of theory. I'm not well acquainted with the state of the art, but Car-Parinello molecular dynamics is a type of density functional theory that can handle potentially large molecules.

@quant_dev - please elaborate on what you mean

@quant_dev - unfortunately there's very little that isn't behind a paywall, but if you don't have an institutional subscription and are happy reading abstracts, this is a decent start. IIRC the authors looked at the active site and proximate protein environment of PSII using a QM simulation (spin-unrestricted density functional theory) embedded in a molecular mechanics simulation. This paper indicates that elements of PSII WOC kinetics are affected by the Jahn-Teller activity of Mn sites.

@nico - Ah, that shows what I know about estrus: I was under the impression that the estral cycle was a single seasonally-modulated cycle rather than a 'cycle within a cycle'. Also didn't know that the chimpanzee menstrual cycle was different. I suspected the periodicity of coral spawning might be an example of an evolutionarily early 28-day clock but wiki seems to suggest that that's a case of an exogenous trigger rather than entrainment.